Ashton attended the Anna Scher Theatre School and National Youth Theatre, and is a graduate of the Manchester Metropolitan University School of Theatre.
Ashton started acting at the age of six.Her television work includes Holby City, EastEnders, The Bill, NCS: Manhunt, Casualty and The Crust. Her theatre credits include Rhinoceros, The Arsonists, Gone Too Far! (Royal Court), Othello (Globe Theatre), and The Cage (Nuffield Theatre Company, Southampton).
In 2009 she worked on the films Blitz and St.